BS ISO 105‑X19:2020 pdf download.Textiles — Tests for colour fastness.
6 Test specimens
6.1 If the textile to be tested is a fabric or textile floor covering, two pieces not less than 220 mm x 30 mm are required for dry rubbing and wet rubbing.
Additional test specimens may be used when higher precision is needed. One test specimen of each pair shall have the long direction parallel to the warp yarns (or in the direction of manufacture), the other parallel to the weft (or filling yarns or at right angles to the direction of manufacture). An alternate method of cutting test specimens is to cut the long dimension diagonally to warp and weft. If the pile lay of a carpet specimen is distinguishable, cut the test specimen with the pile lay pointing in the long direction.
6.2 If the textile to be tested is yarn or thread, two pieces knit it into fabric to provide test specimens of at least 220 mm x 30 mm or form a layer of parallel strands by wrapping it lengthways on a cardboard rectangle of suitable dimensions for dry rubbing and wet rubbing. Wrapped cardboard shall be adhered to the convex specimen stage.
6.3 When testing multi-coloured textiles, care should be taken to position the specimens in such a way that all colours of design are rubbed. Alternatively, if the areas of colour are sufficiently large, more test specimens may he taken, and the individual colours assessed separately.
7 Procedure
7.1 Dry rubbing test
7.1.1 Before testing, condition the test specimen and cotton rubbing cloth for at least 4 h in the temperature of (20 ± 2) °C and the relative humidity of (65 ± 4) % in accordance with ISO 139. Any deviation from this procedure shall he reported. Conditioning is done by laying each test specimen and each piece of cotton rubbing cloth separately on a screen or perforated shelf. Some fabrics such as cotton or wool can require longer periods of conditioning.
Carry out the test at the temperature of(20 ± 2) °C and the relative humidity of(65 ± 4) % in accordance with ISO 139.
7.1.2 Fasten each test specimen by means of clamps to the convex specimen stage so that the long direction of the test specimen follows the track of the convex specimen stage. Some specimens (for example, elastic textile, thin textile, etc.) may be wrinkled and/or moved during the test. In that case, set soft-back water resistant abrasive paper or double-sided tape between the test specimen and the convex specimen stage, it shall be reported.
Attention should be paid to the characteristics of the soft-back water resistant abrasive paper or the double-sided tape used to hold the test specimen, as they can leave an imprint through the textile which can cause a false rating to he made.BS ISO 105‑X19 pdf download.